How do the land structures of iceland confirm seafloor spreading?

There are diverse proofs that support the seafloor spreading. According to the first sample Ocean that indicate that the basaltic ocean had overlying sediments that have become progressively young in them as they approach the ridge from the midst of the ocean. The deposits also cover the thinner areas near the ridge.

The rock makes the floor in the sea to appear small than other continents that did not have samples for more than 200 M years which is a contact to the maximum age of 3M for continental rocks.